Future operational weather radars are likely to implement hybrid polarization, an operating mode that involves transmitting 45° slant polarization and receiving the horizontal and vertical components of the backscattered field. In this work, the degree of polarization at slant send is theoretically considered and experimentally evaluated from fully polarimetric signatures in order to assess its potential for use in next generation operational weather radars.

Abstract-The backscattered field of an illuminated sphere with diameter ∅ = 30.5 cm above a perfect conducting plate is measured in an anechoic chamber at different heights for a varying incidence angle φ in the range 5 • to 75 • . A high frequency field λ ∅ is transmitted, so that two significant transitions from lit to shadow regions are given over the entire incidence angle range for the considered ray field. The polarimetric behavior of the measured scattering matrix [S] is investigated by using the common coherent and incoherent decomposition theorems used by the radar polarimetry scientific community. Close to the shadow boundaries the polarimetric behavior of the sphere significantly changes. Representing the different decomposition parameters used in radar polarimetry over the incidence angle range, the transition zones are related to local maxima or minima. Hence, the extreme values of the polarimetric parameters give information about the geometrical parameters e.g target size and its height above the plate.

ALOS, an enhanced successor of the Japanese Earth Resources Satellite 1 (JERS-1), was launched from JAXA's Tanegashima Space Center in January 2006. An important contribution to the ALOS mission is the verification of PALSAR products to be distributed by the European ADEN node using the PALSAR processor developed by JAXA. A total of 28 ALOS PALSAR products have been analysed with respect to radiometric, geometric and polarimetric quality (including effects of Faraday rotation caused by the ionosphere) and a summary of the results is shown in this paper.

The polarimetric behavior of the diffracted field from an object located close to the ground is investigated for a varying incidence angle. Here, the field is described by the Geometrical Theory of Diffraction (GTD) in accordance to its asymptotic formulas (k → ∞). As a result a ray system composed of 13 different rays was implemented for the monostatic case by applying the principle of Fermat. The different spatial and creeping waves give a physical insight in the mechanisms involved in the entire scattering process. By varying the angle from perpendicular to grazing incidence 0 • − 90 • , geometrical Surface Shadow Boundaries (SSB) are present for the backscattered field. At such boundaries the spatial waves are replaced by their corresponding creeping waves leading to a strong attenuation. The diffracted field for look angles related to the transition zones has a characteristic polarimetric behavior which can be represented on the Poincaré sphere. The typical locations on the sphere can be exploited in order to get information about the geometrical parameters of the target and its height above the ground.

Abstract. Off-shore detection of tsunami waves is a critical component of an effective tsunami early warning system (TEWS). Even more critical is the off-shore detection of local tsunamis, namely tsunamis that strike coastal areas within minutes after generation. In this paper we propose new concepts for near-field tsunami early detection, based on innovative and up-to-date microwave remote sensing techniques. We particularly introduce the NESTRAD (NEar-Space Tsunami RADar) concept, which consists of a real aperture radar accommodated inside a stationary stratospheric airship providing continuous monitoring of tsunamigenic oceanic trenches.